While you are on the site, in your browser find and click "Add to Home Screen" A CGN beaver app icon will then be created to your phone that is directly link to the site.
Note: This feature may not be available in some browsers.
Not a problem. Just about all Glock parts are interchangeable between Glock models. One exception is the trigger housing in a Gen3 will not work in a Gen 4. Others like the extractor, RSA, and ejector is caliber dependant.